Prescription Drug Information: NOXAFIL (Page 5 of 11)

6.2 Postmarketing Experience

The following adverse reaction has been identified during the post-approval use of Noxafil. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency.

Endocrine Disorders: Pseudoaldosteronism

7 DRUG INTERACTIONS

Posaconazole is primarily metabolized via UDP glucuronosyltransferase and is a substrate of p-glycoprotein (P-gp) efflux. Therefore, inhibitors or inducers of these clearance pathways may affect posaconazole plasma concentrations. Coadministration of drugs that can decrease the plasma concentrations of posaconazole should generally be avoided unless the benefit outweighs the risk. If such drugs are necessary, patients should be monitored closely for breakthrough fungal infections.

Posaconazole is also a strong inhibitor of CYP3A4. Therefore, plasma concentrations of drugs predominantly metabolized by CYP3A4 may be increased by posaconazole [see Clinical Pharmacology (12.3)].

The following information was derived from data with Noxafil oral suspension or early tablet formulation unless otherwise noted. All drug interactions with Noxafil oral suspension, except for those that affect the absorption of posaconazole (via gastric pH and motility), are considered relevant to Noxafil injection, Noxafil delayed-release tablet, and Noxafil PowderMix for delayed-release oral suspension as well [see Drug Interactions (7.9) and (7.13)].

7.1 Immunosuppressants Metabolized by CYP3A4

Sirolimus: Concomitant administration of Noxafil with sirolimus increases the sirolimus blood concentrations by approximately 9-fold and can result in sirolimus toxicity. Therefore, posaconazole is contraindicated with sirolimus [see Contraindications (4.2) and Clinical Pharmacology (12.3)].

Tacrolimus: Noxafil has been shown to significantly increase the Cmax and AUC of tacrolimus. At initiation of posaconazole treatment, reduce the tacrolimus dose to approximately one-third of the original dose. Frequent monitoring of tacrolimus whole blood trough concentrations should be performed during and at discontinuation of Noxafil treatment and the tacrolimus dose adjusted accordingly [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.3)].

Cyclosporine: Noxafil has been shown to increase cyclosporine whole blood concentrations in heart transplant patients upon initiation of Noxafil treatment. It is recommended to reduce cyclosporine dose to approximately three-fourths of the original dose upon initiation of Noxafil treatment. Frequent monitoring of cyclosporine whole blood trough concentrations should be performed during and at discontinuation of Noxafil treatment and the cyclosporine dose adjusted accordingly [see Warnings and Precautions (5.1) and Clinical Pharmacology (12.3)].

7.2 CYP3A4 Substrates

Concomitant administration of Noxafil with CYP3A4 substrates such as pimozide and quinidine may result in increased plasma concentrations of these drugs, leading to QTc prolongation and cases of torsades de pointes. Therefore, Noxafil is contraindicated with these drugs [see Contraindications (4.3) and Warnings and Precautions (5.2)].

7.3 HMG-CoA Reductase Inhibitors (Statins) Primarily Metabolized Through CYP3A4

Concomitant administration of Noxafil with simvastatin increases the simvastatin plasma concentrations by approximately 10-fold. Therefore, Noxafil is contraindicated with HMG-CoA reductase inhibitors primarily metabolized through CYP3A4 [see Contraindications (4.4) and Clinical Pharmacology (12.3)].

7.4 Ergot Alkaloids

Most of the ergot alkaloids are substrates of CYP3A4. Noxafil may increase the plasma concentrations of ergot alkaloids (ergotamine and dihydroergotamine) which may lead to ergotism. Therefore, Noxafil is contraindicated with ergot alkaloids [see Contraindications (4.5)].

7.5 Benzodiazepines Metabolized by CYP3A4

Concomitant administration of Noxafil with midazolam increases the midazolam plasma concentrations by approximately 5-fold. Increased plasma midazolam concentrations could potentiate and prolong hypnotic and sedative effects. Concomitant use of Noxafil and other benzodiazepines metabolized by CYP3A4 (e.g., alprazolam, triazolam) could result in increased plasma concentrations of these benzodiazepines. Patients must be monitored closely for adverse effects associated with high plasma concentrations of benzodiazepines metabolized by CYP3A4 and benzodiazepine receptor antagonists must be available to reverse these effects [see Warnings and Precautions (5.6) and Clinical Pharmacology (12.3)].

7.6 Anti-HIV Drugs

Efavirenz: Efavirenz induces UDP-glucuronidase and significantly decreases posaconazole plasma concentrations [see Clinical Pharmacology (12.3)]. It is recommended to avoid concomitant use of efavirenz with Noxafil unless the benefit outweighs the risks.

Ritonavir and Atazanavir: Ritonavir and atazanavir are metabolized by CYP3A4 and Noxafil increases plasma concentrations of these drugs [see Clinical Pharmacology (12.3)]. Frequent monitoring of adverse effects and toxicity of ritonavir and atazanavir should be performed during coadministration with Noxafil.

Fosamprenavir: Combining fosamprenavir with Noxafil may lead to decreased posaconazole plasma concentrations. If concomitant administration is required, close monitoring for breakthrough fungal infections is recommended [see Clinical Pharmacology (12.3)].

7.7 Rifabutin

Rifabutin induces UDP-glucuronidase and decreases posaconazole plasma concentrations. Rifabutin is also metabolized by CYP3A4. Therefore, coadministration of rifabutin with Noxafil increases rifabutin plasma concentrations [see Clinical Pharmacology (12.3)]. Concomitant use of Noxafil and rifabutin should be avoided unless the benefit to the patient outweighs the risk. However, if concomitant administration is required, close monitoring for breakthrough fungal infections as well as frequent monitoring of full blood counts and adverse reactions due to increased rifabutin plasma concentrations (e.g., uveitis, leukopenia) are recommended.

7.8 Phenytoin

Phenytoin induces UDP-glucuronidase and decreases posaconazole plasma concentrations. Phenytoin is also metabolized by CYP3A4. Therefore, coadministration of phenytoin with Noxafil increases phenytoin plasma concentrations [see Clinical Pharmacology (12.3)]. Concomitant use of Noxafil and phenytoin should be avoided unless the benefit to the patient outweighs the risk. However, if concomitant administration is required, close monitoring for breakthrough fungal infections is recommended and frequent monitoring of phenytoin concentrations should be performed while coadministered with Noxafil and dose reduction of phenytoin should be considered.

7.9 Gastric Acid Suppressors/Neutralizers

Noxafil Delayed-Release Tablet and Noxafil PowderMix for Delayed-Release Oral Suspension:

No clinically relevant effects on the pharmacokinetics of posaconazole were observed when Noxafil delayed-release tablets are concomitantly used with antacids, H2 -receptor antagonists and proton pump inhibitors [see Clinical Pharmacology (12.3)]. No dosage adjustment of Noxafil delayed-release tablets or Noxafil PowderMix for delayed-release oral suspension is required when concomitantly used with antacids, H2 -receptor antagonists and proton pump inhibitors.

Noxafil Oral Suspension:

Cimetidine (an H2 -receptor antagonist) and esomeprazole (a proton pump inhibitor) when given with Noxafil oral suspension results in decreased posaconazole plasma concentrations [see Clinical Pharmacology (12.3)]. It is recommended to avoid concomitant use of cimetidine and esomeprazole with Noxafil oral suspension unless the benefit outweighs the risks. However, if concomitant administration is required, close monitoring for breakthrough fungal infections is recommended.

No clinically relevant effects were observed when Noxafil oral suspension is concomitantly used with antacids and H2 -receptor antagonists other than cimetidine. No dosage adjustment of Noxafil oral suspension is required when Noxafil oral suspension is concomitantly used with antacids and H2 -receptor antagonists other than cimetidine.

7.10 Vinca Alkaloids

Most of the vinca alkaloids (e.g., vincristine and vinblastine) are substrates of CYP3A4. Concomitant administration of azole antifungals, including Noxafil, with vincristine has been associated with serious adverse reactions [see Warnings and Precautions (5.7)]. Noxafil may increase the plasma concentrations of vinca alkaloids which may lead to neurotoxicity and other serious adverse reactions. Therefore, reserve azole antifungals, including Noxafil, for patients receiving a vinca alkaloid, including vincristine, who have no alternative antifungal treatment options.

7.11 Calcium Channel Blockers Metabolized by CYP3A4

Noxafil may increase the plasma concentrations of calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, diltiazem, nifedipine, nicardipine, felodipine). Frequent monitoring for adverse reactions and toxicity related to calcium channel blockers is recommended during coadministration. Dose reduction of calcium channel blockers may be needed.

7.12 Digoxin

Increased plasma concentrations of digoxin have been reported in patients receiving digoxin and Noxafil. Therefore, monitoring of digoxin plasma concentrations is recommended during coadministration.

7.13 Gastrointestinal Motility Agents

Noxafil Delayed-Release Tablet and Noxafil PowderMix for Delayed-Release Oral Suspension:

Concomitant administration of metoclopramide with Noxafil delayed-release tablets did not affect the pharmacokinetics of posaconazole [see Clinical Pharmacology (12.3)]. No dosage adjustment of Noxafil delayed-release tablets or Noxafil PowderMix for delayed-release oral suspension is required when given concomitantly with metoclopramide.

Noxafil Oral Suspension:

Metoclopramide, when given with Noxafil oral suspension, decreases posaconazole plasma concentrations [see Clinical Pharmacology (12.3)]. If metoclopramide is concomitantly administered with Noxafil oral suspension, it is recommended to closely monitor for breakthrough fungal infections.

Loperamide does not affect posaconazole plasma concentrations after Noxafil oral suspension administration [see Clinical Pharmacology (12.3)]. No dosage adjustment of Noxafil oral suspension is required when loperamide and Noxafil oral suspension are used concomitantly.

7.14 Glipizide

Although no dosage adjustment of glipizide is required, it is recommended to monitor glucose concentrations when Noxafil and glipizide are concomitantly used.

7.15 Alcohol

Posaconazole was found to release faster from Noxafil PowderMix for delayed-release oral suspension in the presence of alcohol in vitro , which may interfere with its delayed release characteristics. Administration of Noxafil PowderMix for delayed-release oral suspension with alcohol is not recommended [see Clinical Pharmacology (12.3)].

RxDrugLabels.com provides trustworthy package insert and label information about marketed prescription drugs as submitted by manufacturers to the U.S. Food and Drug Administration. Package information is not reviewed or updated separately by RxDrugLabels.com. Every individual prescription drug label and package insert entry contains a unique identifier which can be used to secure further details directly from the U.S. National Institutes of Health and/or the FDA.

As a leading independent provider of trustworthy medication information, we source our database directly from the FDA's central repository of drug labels and package inserts under the Structured Product Labeling standard. RxDrugLabels.com provides the full prescription-only subset of the FDA's repository. Medication information provided here is not intended as a substitute for direct consultation with a qualified health professional.

Terms of Use | Copyright © 2024. All Rights Reserved.